The present invention relates to a method and apparatus for forming and trimming three-dimensional work pieces. The invention is especially suitable for the complete manufacture of complicated three-dimensional work pieces in a single apparatus wherein the forming step is followed by a stamping, cutting, or a trimming step, which takes place in a three-dimensional manner. By the term "three-dimensional work piece" as used herein is meant a work piece having a shape other than planar. The term "three-dimensional tool means" as used hereinafter means a member which when used with a suitable cooperating member is adapted to deform a sheet of material out of a planar configuration or to clamp an article which has been previously deformed into a non-planar configuration.
My U.S. Pat. No. 4,106,379 discloses an apparatus for trimming randomly, three-dimensionally shaped work pieces, wherein the work piece support means have openings through which the strip steel knives pass in the three directions of space, whereby the configuration of all individual knives and their movements provide a three-dimensional cutting or trimming. The apparatus of my U.S. Pat. No. 4,106,379 is not intended for also shaping a three-dimensional work piece in the same machine prior to the stamping, cutting or trimming.
U.S. Pat. No. 4,063,477 discloses an apparatus and method for cutting carpet. A stationary lower support and a vertically movable upper support hold a preshaped carpet in position for the cutting operation. Vertically movable first cutting means travel through the lower and upper support while the supports hold the preshaped carpet in position during the cutting. So-called non-vertical, second cutting means may cut portions of the preshaped carpet which extend in a direction other than the horizontal. Each knife in U.S. Pat. No. 4,063,477 even though it is held in an angular position relative to the horizontal, cuts only in a plane extending perpendicularly to the direction of knife movement. Besides, in this reference the support for the carpet is stationary and therefore the stroke for the cutting knives and for the downholder means must have a substantial length. Moreover, the support means in U.S. Pat. No. 4,063,477 are not relieved from the cutting pressure which may be rather substantial because the forces necessary for the cutting may be in the order of 10 tons or more. Since, in U.S. Pat. No. 4,063,477 the support for the preshaped carpet is stationary, not only the stroke for the cutting knives and for the downholder means must have a substantial length, also each cutting is accomplished only in a respective two-dimensional plane.
U.S. Pat. No. 3,491,639 describes an apparatus for perforating a tubular work piece. The support means for the tubular work piece are not liftable and the known apparatus is not suitable for forming material such as sheet metal or foamable synthetic material into a three-dimensional shape and thereafter providing the three-dimensional shape with trimmed inner and/or outer edges in the same apparatus.